Some progress on cached cashu

After some feedback on how to do a simple POC I decided to not focus on bolt cards and deterministic LNURLw and instead assume that a list of LNURLw can be made from a bolt card and just use a static list of LNURLws for now.

I made the list of LNURLws with LNBits and now have a very simple prototype working where I create some json that contains the encrypted cashu note and a hint (part of) the decryption key.

For this initial demo, I also have the cashu note in plaintext and the full encryption key in plaintext.

Lets see if anyone is able to claim this 1 sat encrypted cached CashU (no cheating: don't just use the plaintext).

Live at http://45.85.249.170:3338/encryptednut/0

```

{ "encrypted_nut": { "cashu_ciphertext": "n7MJbczub-F64wfFEVLbqUPtaAS3E2y8DjeA10MLWR97BJCJs2Y1dwE-ocv6XFkHcZ6KtmEzlr_eJGmBA-gqPeizjC3Ni9g6xQPhTmk2ZcbkHRXXzLi1oJGbom_U4wNRWKAsfXLQme0o-wUPph1fuyAaqGj2hpBrT1jXKrAfZAPDamE5YudMRoDp1NJYn7BkW8VP0VRmkwIN0rhcNwVOSo5piQcyrM6WpkcHgHOBHtXdC7lYescKqAyHacNOmWM85yAmh2-FaS1OlzwIEoLKTGzetoOK5vw2-LaECfL8DEybKDlzTPioXhL0bu-zDPu_OH8NfkX_15_jUx0YzTAZ6YUhHFZ7LYOjHGl-13uwEUA-FpiZUzQaBBxPdgjE0NRkgpvE1KUNpkUXLPq9ohuwzOYJdqteGv_yq6kW61xS0ssm2AgK99djP6ez5BblMWI7nLZxBnz0vWupAwddUhjPw==", "cashu_plaintext": "cashuAeyJ0b2tlbiI6IFt7I....", "encryption_key_full": "LNURL1DP68GURN8GHJ7MR9VAJKUEPWD3HXY6T5WVHXXMMD9AMKJARGV3EXZAE0V9CXJTMKXYHKCMN4WFKZ7DT5WU6HZ4ZXG35K7MJKDG6HX3T4GEGHW4F59AF8JU2TGSMYV6Z3VD58G625WDQ5ZNJDXDU8ZMRH2K0", "encryption_key_hint": "LNURL1DP68GURN8GHJ7MR9VAJKUEPWD3HXY6T5WVHXXMMD9AMKJARGV3EXZAE0V9CXJTMKXYHKCMN4WFKZ7DT5WU6HZ4ZXG35K7MJKDG6HX3T4GEGHW4F59AF8JU2TGSMYV6Z3VD58G625WDQ5ZNJDXDU8ZMRH2K", "index": 0, "key": "198a1a4ee777d059d5f8e255deaa7f175a16d67aee667e6fa90802d4fcad9987" }, "index": 0, "lnurlw": "LNURL1DP68GURN8GHJ7MR9VAJKUEPWD3HXY6T5WVHXXMMD9AMKJARGV3EXZAE0V9CXJTMKXYHKCMN4WFKZ7DT5WU6HZ4ZXG35K7MJKDG6HX3T4GEGHW4F59AF8JU2TGSMYV6Z3VD58G625WDQ5ZNJDXDU8ZMRH2K0" }

```